Make sure there are no extra spaces before or after the serial number.

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If you apply a Software Update and are then presented with the invalid serial number alert, the next time you open the software, try removing your System ID file&lpar;s&rpar; and entering your serial number&lpar;s&rpar; again:&NewLine;&Tab;

The System IDs are located here:&NewLine;&Tab;

/Library/Application Support/ProApps/

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If present, remove the appropriate file for the software you're attempting to serialize, then launch the application and enter your serial number.

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Make sure that the serial number is valid for the product you're trying to serialize, for example:&NewLine;&Tab;

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Soundtrack serial numbers are not valid for serializing Soundtrack Pro.

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Academic or NFR &lpar;Not for Resale&rpar; serial numbers cannot be used with an upgrade version.